unconcern vs vivaciousness

unconcern

noun
  • Lack of interest or care; indifference or apathy. 

  • Freedom from worry or apprehensiveness; insouciance or nonchalance. 

vivaciousness

noun
  • the state of being vivacious; vivacity 

How often have the words unconcern and vivaciousness occurred in a corpus of books? (source: Google Ngram Viewer )